When a connector ingests data, it passes the data through an index pipeline for transformation prior to indexing. The format of your indexed data depends on the index pipeline, which is part of the datasource configuration.
An index pipeline consists of one or more configurable index pipeline stages, each performing a different type of transformation on the incoming data. Each connector has a default index pipeline, but you can modify these or create new ones.
The last stage in any index pipeline should be the Solr Indexer stage, which submits the documents to Solr for indexing.
In some cases, you might want to send data to be indexed to an index profile, instead of directly to an index pipeline.
An index profile is an indexing endpoint that hides the index pipeline and collection from a search app, and that can be used to specify configuration parameters for the index pipeline.